JP2015063804A - Optical sensor for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical sensor for a vehicle, achieving low power consumption and having high detection accuracy.SOLUTION: An optical sensor for a vehicle includes: a light emission part 3 which projects detection light from an outer wall part of a vehicle 1 to a detection area 2 set outside the vehicle 1 at predetermined intervals; and a determination part 6 which detects approaching of a detection object 5 into the detection area 2 by a received amount of light at a receiver 4 to the detection light from the detection area 2. The light emission part 3 projects the detection light with a pulse group consisting of a plurality of kinds of pulses having different light emission amounts of light as a unit regardless of the received amount of light at the receiver 4, and the determination part 6 amplifies and corrects the received amount of light to each pulse by an amplification factor using a ratio of light emission amount of light as a reference and makes it an evaluation object.

Description

  The present invention relates to a vehicle optical sensor.

  As an optical sensor with improved detection accuracy, one described in Patent Document 1 is known. In this conventional example, the optical sensor includes a light emitting element and a light receiving element. When the light receiving intensity in the light receiving element decreases, the light emitting element increases the light emitting intensity. When the light receiving intensity is high, the light sensor emits light. It is comprised so that the emitted light intensity of an element may be reduced.

JP 2001-133550 A

  However, since the conventional example described above increases the detection accuracy by increasing the light emission intensity with respect to the decrease in the light reception intensity, the decrease in the light reception intensity is caused by a relatively long-term cause such as contamination of the light emitting element. In this case, the high light emission state becomes constant, the battery consumption increases remarkably, and the battery consumption cannot be assumed in advance.

  For this reason, there exists a problem that it is not suitable for the optical sensor used for the use which monitors the state in the stop of the private vehicle which does not receive the electric power supply from a commercial power source etc.

  In order to solve this problem, it is possible to increase the amplification factor on the light receiving side when the received light intensity decreases, but in order to change the amplification factor according to the received light intensity, a complicated circuit configuration is required. Not only is this necessary, but the signal-to-noise ratio also decreases, so that there is a problem that the detection accuracy also decreases.

  The present invention has been made to solve the above-described drawbacks, and an object of the present invention is to provide a vehicle optical sensor with low power consumption and high detection accuracy, and a vehicle door opening / closing control device using the same. .

According to the present invention, the object is
A light emitting unit 3 that projects detection light at a predetermined interval from the outer wall of the vehicle 1 toward a detection region 2 set outside the vehicle 1;
A determination unit 6 that detects the entry of the detection target 5 into the detection region 2 based on the amount of light received by the light receiving unit 4 from the detection region 2 with respect to the detection light;
The light emitting unit 3 projects detection light in units of pulse groups composed of a plurality of types of pulses with different light emission amounts regardless of the amount of light received by the light receiving unit 4.
The determination unit 6 is achieved by providing a vehicle optical sensor to be evaluated by amplifying and correcting the received light amount with respect to each pulse by an amplification factor based on the ratio of the emitted light amount.

  The vehicle optical sensor (A) receives the reflected light from the detection region 2 by the light receiving unit 4 in accordance with the irradiation timing of the detection light to the detection region 2 of the light emitting unit 3, and moves to the detection region 2 by the change in the light reception level. It is comprised so that the approach of the detection object 5 may be detected.

  The detection light from the light emitting unit 3 is emitted as a pulse group including a plurality of types of pulses having different light emission amounts, and the determination unit 6 substantially determines the received light amount in the light receiving unit 4 corresponding to each constituent pulse in the pulse group. By using the value amplified by the amplification factor based on the ratio of the emitted light quantity as a determination target, the detection operation of the detection target 5 is performed by pretending to be the received light quantity by the same light quantity.

  Therefore, in the present invention, as shown in FIG. 3 (a), when the amount of received light is reduced due to dirt on the sensor or the like, when the decrease in the amount of received light is compensated for by increasing the amount of emitted light, the power consumption changes depending on the state of the stain. In addition, it is difficult to predict, and furthermore, an increase in power consumption due to prolonged dirt is unavoidable. On the other hand, the amount of light emitted from the light emitting unit 3 is constant regardless of changes in the amount of received light. In addition, the power consumption is constant regardless of the degree of contamination of the sensor, and it is possible to accurately grasp the power consumption. In addition, since the low light emission pulse is included, the overall power consumption must be kept low. Can do.

  Also, in order to amplify the received light amount of the received light pulse with a constant amplification factor regardless of the change in the received light amount, the signal processing is simplified compared to when the amplified amount is changed with the change in received light amount due to dirt etc. And the burden on the calculation unit is reduced.

Also,
If the vehicle light sensor is configured such that the light emission interval between the high light emission amount pulse and the subsequent pulse in the pulse group is longer than the interval between other pulses, the power consumption can be further reduced.

Furthermore, the vehicle light sensor
The determination in the determination unit 6 for the low light emission amount pulse is configured to be executed with a statistical representative value defined by an amplification correction value for the pulse and an evaluation value for an appropriate number of preceding pulses as an evaluation target. be able to.

  The amplification correction compensates for the difference between the light emission amounts of the low light emission light amount pulses by amplification. By further performing statistical processing on these amplification correction values, noise components mixed during amplification are statistically removed. And detection accuracy can be further increased.

  As a statistical representative value for the pulse to be evaluated, a moving average having a proper number of preceding pulses and an evaluation target pulse as elements, or a median (median value) or the like can be used.

Moreover, the vehicle door opening / closing control device using these vehicle optical sensors (A)
A vehicle optical sensor (A);
A door control unit 9 that opens the vehicle door 8 by operating the actuator 7 on condition of a detection confirmation signal of the detection target 5 in the vehicle optical sensor (A) can be configured.

  In the present invention, when the door control unit 9 receives the detection confirmation signal, the door control unit 9 is in a locked state on condition that a predetermined other condition such as that the unlocking operation authority is authenticated by an appropriate authentication unit is satisfied. The release and opening operation signal of the vehicle door 8 is output to the actuator 7, and the opening operation of the door is performed. As a result, the door can be opened simply by inserting a load, a hand or the like into the detection area 2 in a state where the unlocking conditions are satisfied, so that convenience is improved.

  According to the present invention, since the pulse group including the low emission light amount pulse is used as the detection light regardless of the change in the received light amount, the increase in the emission light amount can be achieved even when the sensor is dirty for a long time. Therefore, the power consumption can be kept low as a whole, and the received light quantity with respect to the low light quantity is amplified and evaluated, so that the detection accuracy can be prevented from being lowered.

It is a figure which shows the vehicle by which the vehicle door opening / closing control apparatus was used, (a) is a rear view, (b) is a side view, (c) is the 1C-1C sectional view taken on the line of (a). It is a functional block diagram which shows this invention. FIG. 5 is a diagram showing the irradiation state of detection light with time on the horizontal axis and the irradiation light amount on the vertical axis, where (a) shows no conventional example, and (b) shows the trading company state of detection light according to the present invention; (c) is a figure which shows the modification of (b).

  FIG. 1 shows a vehicle 1 in which a vehicle door opening / closing control device is used. In this example, the vehicle door opening / closing control device is configured as a back door control device for controlling the opening / closing operation of a power back door driven by an actuator 7 such as a damper device. 8) the vehicle optical sensor (A) fixed to 8), and a door control unit 9 for controlling the actuator 7.

  As will be described later, the optical sensor (A) is configured to output a detection confirmation signal when detecting the entry of the detection target 5 into the predetermined detection area 2 where the detection light is projected. It is a sensor and is fixed to the ceiling wall portion of the license plate mounting recess 11 surrounded by the license plate finisher 10. In FIG. 1, reference numeral 12 denotes a license plate.

  Further, in this example, in order to position the center of the detection region 2 of the optical sensor in the license plate mounting recess 11, the optical axis of the detection light is slightly inclined inward of the vehicle 1 (angle θ). Thereby, since the detection ability outside the license plate mounting recess 11 is reduced, it is possible to prevent the optical sensor from inadvertently reacting in the state where a person other than the user, an animal, garbage, or the like approaches the vehicle 1.

  In this example, when a detection confirmation signal is output from the optical sensor (A), the door control unit 9 first prepares for authentication of an electronic key possessed by the user, detection of the state of the back door 8, locking and unlocking operation, and the like. After the operation, the actuator 7 is driven. The authentication of the electronic key is performed by communicating with an authentication device (not shown) and authenticating the authentication code output from the electronic key. When the authentication is established, the back door 8 is in a closed condition on the condition that the back door 8 is in a closed state. After unlocking operation 8, the actuator 7 is driven to start the door opening operation.

  Therefore, in this embodiment, even if the hand is blocked by a luggage or the like, it is only necessary to bring the luggage or the like to be detected 5 close to or near the license plate mounting recess 11 set as the detection area 2. Convenience is improved because the back door can be opened.

  As shown in FIG. 2, the optical sensor (A) includes a light emitting unit 3 using an infrared LED as a light source, a light receiving unit 4 including a light receiving circuit including an infrared light receiving element, and a control unit 13. 13 includes a light emission control unit 13a, a light reception control unit 13b, an amplification unit 13c, a statistical processing unit 13d, and a determination unit 6.

  The light emission control unit 13a controls the light emitting unit 3 so as to emit detection light at a predetermined interval in units of a pulse group (pu) including a predetermined number of pulses (p) having different light emission amounts. In this example, as shown in FIG. 3B, each pulse group (pu) includes two types, a high emission light amount pulse (ph) having a high light emission amount and a low emission light amount pulse (pl) having a low light emission amount. Each pulse is irradiated with a predetermined light amount and timing without changing the light amount and the output timing even if the amount of received light is reduced due to contamination of the sensor or the like.

  Further, the light emission control unit 13a outputs the light emission timing to the light reception control unit 13b and the light amount information at the light emission timing to the amplification unit 13c.

  The light receiving control unit 13b controls the light receiving unit 4 to receive the reflected light from the detection region 2 in synchronization with the output of the pulse (p) in the light emitting unit 3, and the output from the light receiving unit 4 is the amplification unit 13c. Is amplified and output to the statistical processing unit 13d.

  The amplification unit 13c has a predetermined amplification factor that corresponds to the light amount information from the light emission control unit 13a and is approximately proportional to the light emission amount. When the light amount information is received from the light emission control unit 13a, a predetermined amplification factor is applied. Then, amplification correction is performed on the output from the light receiving unit 4.

  The amplifying unit 13c can be a so-called electronic amplifying circuit, or the output from the light receiving unit 4 can be digitally output and obtained as a product of an output value and an amplification factor, and the amplifying unit 13c can be obtained as an electronic amplifying circuit. In this case, the light amount information from the light emission control unit 13a is output as switch information of the amplifier circuit.

  The statistical processing unit 13d statistically processes the output value from the amplifying unit 13c and removes a protruding value or the like due to noise, and the output value and an appropriate number set in advance preceding the output value. A statistical representative value (the median in this example) with the output value is output to the determination unit 6 as an evaluation target value.

  The determination unit 6 that has received the evaluation target value outputs a detection signal when the evaluation target value exceeds a preset threshold value, and the control unit 13 outputs a detection confirmation signal to the door control unit 9.

  In the above description, the case where the detection light is constituted by a pulse group (pu) composed of two kinds of light emission level pulses (ph, pl) is shown. Further, as shown in FIG. 3C, the power consumption can be suppressed by increasing the interval between the high emission light amount pulse and the subsequent pulse.

  Further, as the statistical representative value used in the statistical processing unit, a function frequently used as a digital noise removal filter such as a moving average value in addition to the median value can be used.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Detection area 3 Light-emitting part 4 Light-receiving part 5 Detection object 6 Judgment part 7 Actuator 8 Vehicle door 9 Door control part A Vehicle optical sensor

Claims (4)

A light emitting unit that projects detection light at a predetermined interval from a vehicle outer wall toward a detection region set outside the vehicle;
A determination unit that detects the entry of the detection target into the detection region based on the amount of light received by the light receiving unit from the detection region with respect to the detection light;
The light emitting unit projects detection light in units of a pulse group composed of a plurality of types of pulses having different light emission amounts regardless of the amount of light received by the light receiving unit,
The determination unit is a vehicle optical sensor to be evaluated by amplifying and correcting a received light amount with respect to each pulse by an amplification factor based on a light emission amount ratio.   The vehicle optical sensor according to claim 1, wherein a light emission interval between a high light emission amount pulse and a subsequent pulse in the pulse group is made longer than other pulse intervals.   The determination by the determination unit for the low light emission amount pulse is executed by using a statistical representative value defined by an amplification correction value for the pulse and an evaluation value for an appropriate number of preceding pulses as an evaluation target. The optical sensor for vehicles as described. The vehicle optical sensor according to claim 1,
A vehicle door opening / closing control device having a door control unit that operates an actuator to open a vehicle door on condition of a detection confirmation signal of a detection target in a vehicle optical sensor.

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